Since arriving at Mars in 2012, NASA's Curiosity rover has drilled into rocks in search of organics – molecules containing carbon. Organics are the building blocks of all life on Earth, though they can also come from non-living sources. The surface of Mars readily destroys these molecules, making them difficult to detect. Now, Curiosity has discovered ancient organics that have been preserved in rocks for billions of years. This finding helps scientists better understand the habitability of early Mars, and it paves the way for future missions to the Red Planet.

Curiosity poses for a self-portrait, along with one of the organic molecules that it discovered. On the ground next to the rover are two small drill holes marking the site of the discovery, in a sedimentary rock named "Mojave 2."